Financial Derivatives - Schedule of Net Income/(Expense) Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Investments and cash equivalents	$ 21,581	$ 4,121	$ 38,497	$ 14,107
Interest Income Farmer Mac Guaranteed Securities and USDA Securities	74,695	42,339	169,231	127,976
Interest Income Loans	97,514	61,923	241,393	181,631
Total interest expense	(125,937)	(49,467)	(251,816)	(155,599)
Gains/(losses) on financial derivatives	772	(888)	21,551	2,581
Total	68,625	58,028	218,856	170,696
Expense recognized on cash flow hedges	4,192	3,250	33,272	14,855
Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(159,661)	(43,732)	(488,481)	(212,845)
Gains/(losses) on fair value hedging relationships	(625)	1,992	5,953	1,432
Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(15)	(11)	(43)	(25)
Interest settlements reclassified from AOCI into net income on derivatives	1,072	(1,932)	(2,094)	(5,454)
Recognized on hedged items	(4,046)	(685)	(6,654)	(1,983)
Expense recognized on cash flow hedges	(2,989)	(2,628)	(8,791)	(7,462)
Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	19,974	28,088	76,840	88,670
Premium/discount amortization recognized on hedged items	(608)	(287)	(2,294)	(765)
No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	772	(888)	21,551	2,581
Interest Income Investments and Cash Equivalents | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(52,308)	(1,737)	(108,002)	(1,549)
Gains/(losses) on fair value hedging relationships	(2,935)	90	(1,067)	102
Interest Income Investments and Cash Equivalents | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Recognized on hedged items	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Income Investments and Cash Equivalents | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	4,617	274	10,433	341
Premium/discount amortization recognized on hedged items	(59)	0	(816)	0
Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(204,765)	(31,523)	(564,679)	(150,445)
Gains/(losses) on fair value hedging relationships	(2,901)	2,449	(782)	3,743
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Recognized on hedged items	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	35,763	28,937	102,123	90,278
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Interest Income Loans | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(100,490)	(19,184)	(337,443)	(99,955)
Gains/(losses) on fair value hedging relationships	5,193	468	9,591	321
Interest Income Loans | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Recognized on hedged items	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Income Loans | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	14,857	11,817	41,146	34,940
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Total Interest Expense | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	197,902	8,712	521,643	39,104
Gains/(losses) on fair value hedging relationships	18	(1,015)	(1,789)	(2,734)
Total Interest Expense | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(15)	(11)	(43)	(25)
Interest settlements reclassified from AOCI into net income on derivatives	1,072	(1,932)	(2,094)	(5,454)
Recognized on hedged items	(4,046)	(685)	(6,654)	(1,983)
Expense recognized on cash flow hedges	(2,989)	(2,628)	(8,791)	(7,462)
Total Interest Expense | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(35,263)	(12,940)	(76,862)	(36,889)
Premium/discount amortization recognized on hedged items	(549)	(287)	(1,478)	(765)
Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Gains on financial derivatives | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	0	0	0	0
Gains/(losses) on fair value hedging relationships	0	0	0	0
Gains on financial derivatives | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Recognized on hedged items	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Gains on financial derivatives | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	0	0	0	0
Premium/discount amortization recognized on hedged items	0	0	0	0
Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	772	(888)	21,551	2,581
Interest Rate Swap | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(20,235)	(17,091)	(52,622)	(54,150)
Income/(expense) related to interest settlements on fair value hedging relationships	(869)	10,710	21,924	33,755
Recognized on derivatives	159,036	45,724	494,434	214,277
Interest Rate Swap | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	5,054	(634)	10,954	(662)
Expense recognized on cash flow hedges	(2,613)	168	(5,496)	3,489
Interest Rate Swap | Interest Income Investments and Cash Equivalents | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	957	(141)	(1,536)	(177)
Income/(expense) related to interest settlements on fair value hedging relationships	5,515	133	8,081	164
Recognized on derivatives	49,373	1,827	106,935	1,651
Interest Rate Swap | Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Rate Swap | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(350)	(20,925)	(37,687)	(63,966)
Income/(expense) related to interest settlements on fair value hedging relationships	35,413	8,012	64,436	26,312
Recognized on derivatives	201,864	33,972	563,897	154,188
Interest Rate Swap | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Rate Swap | Interest Income Loans | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	1,837	(6,911)	(9,568)	(20,185)
Income/(expense) related to interest settlements on fair value hedging relationships	16,694	4,906	31,578	14,755
Recognized on derivatives	105,683	19,652	347,034	100,276
Interest Rate Swap | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Rate Swap | Total Interest Expense | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(22,679)	10,886	(3,831)	30,178
Income/(expense) related to interest settlements on fair value hedging relationships	(58,491)	(2,341)	(82,171)	(7,476)
Recognized on derivatives	(197,884)	(9,727)	(523,432)	(41,838)
Interest Rate Swap | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Rate Swap | Gains on financial derivatives | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	0	0	0	0
Income/(expense) related to interest settlements on fair value hedging relationships	0	0	0	0
Recognized on derivatives	0	0	0	0
Interest Rate Swap | Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	5,054	(634)	10,954	(662)
Expense recognized on cash flow hedges	(2,613)	168	(5,496)	3,489
Treasury futures | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	(1,669)	(422)	16,093	(246)
Treasury futures | Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Treasury futures | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Treasury futures | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Treasury futures | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	0	0	0	0
Treasury futures | Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on financial derivatives	$ (1,669)	$ (422)	$ 16,093	$ (246)